Copyright © 2020 Albuquerque Journal
Even though disinfectant has been cleared off the shelves in some grocery stores, some of the most powerful sterilizer available can’t be bottled.
UV light is known to disrupt germs, breaking down cell walls and killing them, but it takes more than just a spray bottle to use this kind of cleaning method.
This is why Doctor Mark Stibich invented the Xenex UV light disinfecting robot. The robot is used by hospitals, including the Mayo Clinic, Westin Hotels & Resorts and the Ruidoso Municipal School District.
Now, the robot is even being used to kill the novel coronavirus causing the COVID-19 pandemic. This UV light technology was even referenced by President Donald Trump and the U.S. Centers for Disease Control.
Stibich, who lives in Santa Fe, is an infectious diseases epidemiologist, trained at Johns Hopkins School of Public Health. He studied UV light as a disinfectant at the MD Anderson Cancer Center in Albuquerque. Through his studies, he was able to prove that UV light can be used in a hospital setting and is more than 20 times more effective than traditional housekeeping disinfectants.
Hospital surfaces were difficult to disinfect and clean properly, he said, and that’s why he developed a “pulsed xenon ultraviolet system” to kill bacteria, viruses, molds and other microbes.
The robot specifically uses UV-C light, which is emitted by the sun, but filtered out through the ozone. The robot emits UV-C wavelengths across the entire UV-C spectrum, which can break down a cell wall.
“So that means it doesn’t naturally occur on Earth, so bacteria, viruses, they’ve never been exposed to it. They’ve never evolved any kind of defenses against it,” Stibich said. “When an organism is exposed to that, it can basically fuse the information in their DNA and RNA, causing enough damage that the organism can no longer replicate.”
No one should be directly exposed to the robot’s light, Stibich said, and the robot is equipped with such safety features as motion sensors.
George Bickert, Ruidoso Municipal Schools superintendent, said he first came across the robot when he was researching what other industries were using to clean during the pandemic. The district’s school board approved the purchase of six robots at a cost of $720,000 in July and the robots were delivered in August.
“The robots are fantastic,” Bickert said. “They give us an added layer of protection and security in terms of keeping our facility safe and clean. We use them in all of our classrooms. When we had students, we made sure that we hit any areas where we might have had a person who had tested positive.”
The robots were a serious investment, Bickert said, and the district plans to use them well past the pandemic. He said the schools will use them during the regular flu season, in locker rooms to prevent staph infections, and more.
But schools and hospitals aren’t the only place using UV light technology.
Dorothy School, a University of New Mexico biology professor, said in an email that the biology department uses UV-C light in the biology safety cabinet hoods as a disinfectant. These hoods are used to work with pathogens, including COVID-19, tuberculousis and Lyme disease bacteria.
She said the light is effective at sanitizing the hoods, which are used to perform molecular biology techniques.
“UV works as a general sterilizer for tissue samples and, more specifically, for COVID because it disrupts the protein coat of the SARS-CoV-2 virus,” she wrote. “The virus needs that protein coat in order to remain infectious.”
UNM faculty have also conducted research into how UV light can be used to combat the pandemic.
David Whitten, Department of Chemical and Biological Engineering professor, along with Eva Chi and Linnea Ista, recently published a report in the journal ACS Applied Materials & Interfaces about their UV light discoveries.
They found that a combination of polymers and oligomers, when activated with UV light, can almost completely kill the virus, according to a news release. These materials can be applied to N95 masks to help lengthen the lifespan and effectiveness of personal protection equipment.
There’s also no evidence that germs would become resistant to UV disinfectant like they can with antibiotics and other methods, they say.
In the study, pathogens were exposed to UV light for 25 different growth cycles and after the 25th cycle, there was still no evidence of UV resistance, Stibich said.
Stibich said the mission of his company is to reduce the deaths caused by infections. Right now, everyone’s mind is on COVID-19, but before the virus there was still plenty of work to do. There are over 2 million health care-associated infections a year in the United States, he said.
If an infection can be prevented in the first place, Stibich said, it can not only potentially change someone’s life, but also preserve antibiotics for someone else.